Motorola coldfire520X and gcc/gdb

Tony Armitstead
Mon Jun 9 04:11:00 GMT 1997

> > On Fri, 6 Jun 1997, Chris Johns wrote:
> > 
> > I got it from a friend of mine, but you can also find it on 
> >
> > I'm not sure about the directory, but I think /pub/gdb
> > file is gdb-bdm-patches.tar.gz or similar.
> > 
> > the patch is relative to gdb-4.13 but I patched a gdb-4.16 with it
> > (had to tweak the gdb/Makefile)
> I did the 4.13 patches some time back, when I still was at the University.
> The patches have somehow wandered to Cygnus, but haven't been updated since
> then. 
> Rob: If you read this, could you please add a pointer in
> to the URL below? 4.13 is definately obsolete.
> Last summer I did the move to 4.16 and added some more features.
> see:
> A word to porting the driver and the gdb patches to ColdFire:
> Unfortunately I have neither a ColdFire-System nor a data book available,
> but I have heard there are more features in the ColdFire BDM interface,
> than in CPU32 (trigger capability on access to specific addresses). 
> The driver for CPU32 and CPU32+ boils down to send the BDM commands over
> the BDM send/receive line. _If_ this is still a 10/8 pin connector with the
> same timing, you can use the many available PD parallel port BDM
> interfaces, and so probably the driver with only minor changes. But this
> needs very careful checking re. timing, etc.  Especially the single
> stepping is very critical. However, it seems workable.

Sorry chaps but the BDM interface on Coldfire is very different from 
that on CPU32 - it also uses a 26 pin connector and not the CPU32 
8 or 10 pins. However it is a much better BDM interface than CPU32 in 
that it allows dynamic access to memory, on-chip breakpoints (better 
than 68360) and nearly non-intrusive tracing of program execution.

On the down side you cant do a simple BDM parallel cable interface 
since the BDM serial transfer has to be synchronised to the CPU which 
is just not possible without some extra hardware in the cable header.

I should point out that Noral who I work for makes BDM interfaces for 
both CPU32 and Coldfire ... but I will say no more.


Tony Armitstead         
Noral Micrologics Ltd.
Logic House, Gate St. 
Blackburn, Lancs.                 Tel: 01254 682092
England, UK.                      Fax: 01254 680847

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